Circuit controller



April 20; 1.943- i l G. F. sAUERs I 2,316,977'

CIRCUIT CONTROLLER Filed Oct. 9, 1941 3 Sheets-Sheet l Z4 Y 23 Z4 Ifir/71 v l l ,Il 111,1

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Apil 20, 1943. G. F. `SAUL-:Rs l 2,316,971

CIRCUIT CONTROLLER Filed oct. 9, 1941'.

3 Sheets-Sheet 2 l WITNEssl-:s: INVENToR Gordo/7 1527 uefa @7i/8m' l n@gi/M Ap zo, 1943.I

G. F. SAUERS CIRCUIT CONTROLLER Filed Oct. 9, 1941 3 Sheets-Sheet 3INVENTOR @Ora/0p FSOI/e/.

BY 5l/ l d ATTRN WITNEssEs:

Patented Apr. 20, 1943 CIRCUIT CONTROLLER Gordon F. Sauers, Pittsburgh,Pa., assigner to Westinghouse Electric & Manufacturing Company, EastPittsburgh, Pa., a corporation of Pennsylvania Application October 9,1941, Serial No. 414,292

(Cl. ZOO- 169) 16 Claims.

This invention relates generally to electric switching devices, and moreparticularly, to selective switching devices.

Where for the purpose of obtaining continuity of service, a plurality offeeder lines may be available for supplying a station bus structure orthe like, it is important from the standpoint of synchronization andsafety considerations that the transfer from one feeder to anothershould not be accomplished too quickly.

One object of this invention is to provide a novel transfer switch meanswhich requires that the transfer switch be stopped at an intermediateopen circuit position, during a transfer operation.

Another object of this invention is to provide novel means forreleasably locking a disconnecting switch in an open circuit positionand in a closed circuit position.

Another object of this invention is to provide a novel transfer switchof the type described wherein during a transfer operation it is requiredthat the operator stop the switch at an intermediate open circuitposition, and perform another operation before the transfer operationcan be completed.

Another object of this invention is to provide a transfer switch withnovel means for locking the switch in its closed circuit position and inan open circuit position.

These and other objects of this invention will become more apparent uponconsideration of the following detailed description of a preferredembodiment thereof when taken in connection with the attached drawings,in which:

Figure 1 is a longitudinal sectional view of an enclosed switchstructure embodying the invention, with the switch and operatingmechanism shown in elevation;

Fig. 2 is a view similar to Fig. 1 but taken at right angles to thesection of Fig. 1;

Fig. 3 is an enlarged View of a portion of the switch operatingmechanism; and

Fig. 4 is a section taken substantially on the line IV--IV of Fig. 3.

Although the invention will be hereinafter par-A ticularly disclosed inconnection with a threephase enclosed switching unit, it will be obviousthat the invention is also capable of use with a` single switch, or withany number of gang-operated switches. Certain aspects of the inventionmay also be useful in switches which are not enclosed.

Referring more particularly to the drawings,`

there is shown in Figs. 1 and 2 a switch enclosure 2 which may be ofsheet metal or the like and essential to an understanding of thisinvention..

Front wall 4 is provided with a door 5 which may be movably secured onfront wall 4 in any desired manner. Within the switch enclosure 2 thereis provided a pair of supporting partitions, the upperV one I4 beingsecured to an angle iron support I8A which, in turn, is secured to thewalls of the enclosure, for example, as by welding or the like. Thelower supporting partition I2 is mounted similar to the upper partitionI4 on an angle iron support I6, also secured to the Walls of theenclosure. The upper supporting partition I4 is provided with spacedpairs of spaced apertures, for receiving insulators 20, each of which isprovided with an annular supporting flange 2I formed on a collar securedsubstantially at the center of the insulators, so that the insulatorsmay be supported in the apertures of partition I4 by having flanges 2Ithereof bolted, or otherwise secured to the partition I4. Each of theinsulators 20 supports at its lower end, a break terminal or contact 22,and as shown in Fig. 1, the break contacts of each pair of insulators 20are directed angularly towards each other, for a purpose to behereinafter described. Each break contact 22 is provided with anintegral stem extending through a longitudinal central aperture throughits associated insulator 20, and this stem is provided with a threadedouter end 24 for receiving a `clamping nut 26, to secure the jaw inoperative position fixed relative to its insulator. Nuts 28 may be alsoprovided for the threaded stem of the break contacts for the purpose ofsecuring a conductor thereto for electrically connecting the contact ina circuit.

The partition I2 is provided with a row of substantially centrallylocated apertures for receiving insulators 30 similar to insulators 20,with theinsulators positioned immediately below a pair of insulators 20and positioned substantial- 1y intermediate the insulators 20 and breakjaws 22. Each' insulator 30 is also provided with a flanged collar 32similar to the flanged co1lar'2I on insulators 20, for the purpose of'securing the insulators to` supporting partition I2. Insulators 30support hinge contacts 34 at their upper end, and these contacts, likethe break contacts 22, are provided with integral stems extendingthrough insulators 30 and having threaded outer portions 36 forreceiving a securing nut 38, and conductor clamping nuts 40.

A split blade 42 is adapted to be pivotally for engaging the hingecontact 34, as well as break contacts 22, and these may assume the formshown, for example, in the copending application of H. J. Crabbs, SerialNo. 268,906, filed April 20, 1939, and issued November 11, 1941 asPatent No. 2,262,168 to the same assignee of this application. Thespecific construction of split blade 42 and the manner in which it issecured to hinge contact 34, and the manner in which the other ends ofthe blade sides are secured together by bolt 58 and washers 52, aresimilar to that disclosed in the above-mentioned Crabbs patent,

and accordingly, for more complete description of these parts, referenceis hereby made tothe aforesaid patent.

As shown, the upper end of blade 42 is in a position intermediate onepair of break contacts 22, and it will be apparent that by pivotal'movement of blade 42 about its pivot 46 on the hinge. contact, the upperend thereof may be moved into engagement with either one of break jaws22 shown in Fig. 1. The break jaws are provided with notches 54 forreceiving the portion of bolt 50 connecting the outer ends of bladesides 44..

A switch actuating shaft 56 is preferably mounted adjacent front wall` 4of the switch` en:

closure and is adapted to extend the entire length of the enclosure tobe mounted in bearings 51 at opposite ends thereof, which bearings aresecured to end walls 8 and l0 of the enclosure by brackets 59. Bearings5'! may be bolted tofthe brackets as shown, and the brackets may besecured to the casing walls by welding or the like, On the end of shaft56 adjacent end Wall I8, there is secured an operating casting 60 fixedto rotate with the shaft, and-as shown is preferably in the shape of acircular segment.Y The' operating casting 6b is preferably of a size so`that in all positions of the switch a portion of the circular peripheryof the block projects 4through an opening 58 provided in door 5. Thereis also mounted on actuating shaft 56 at points substantially oppositeeach of switch blades 42, a crank BI rigidly secured to the shaft. Thecrank 6| may comprise separate threadedly engagea-ble parts forproviding longitudinal adjustment thereof to obtain simultaneousmovement of the blades into and out of engagement with their respectivebreak contacts. The outer ends of cranks 6I are connected to blades 42,respectively, by connecting links 62 of insulating material, such forexample, as ber or the like, which are pivoted to the cranks as at 65,and to the midportion of Vblade 42 as at 64, withv the link receivedbetween the sides of the split blade.

Operating casting 60 is provided with a pair of substantially radiallyextending bores 68 and 1.0 providing sockets for receiving an actuatinghandle. Each socket is provided with a reduced inner end portion 12terminating short of actuating shaft 5'5, and adjacent the reducedportion of the bores, there is provided a lateral opening 14 in theplane of the bores, and elongated for a short distance inthe directionof the bores. These lateral slots 14,arefor the purpose of slidablyreceiving locking pins or lugs 'l5 extending engagement with fixed stop"projection 82.

laterally through slots 14 and having collars 18 fixed thereto, by anysuitable means, and positioned on opposite 'sides of the operatingcasting Si! to prevent endwise movement of the pins relative to theblock. As shown in Figs. 2 and 4, one end of pins 'i6 is extendedconsiderably beyond the side of the. operating casting adjacent wall 4as at 19, so as to be engageable with'a fixed stop projection 82 mountedon wall 4, when the pins are in their outermost position. Pins 'I6 arenormally biased to their outermost position in slots 74, by coilcompression springs engageable between pins 16 and the bottom of reducedportion T2; of the bores.

With. the structure provided in an intermediatie openy circuit position,as shown in Fig. 1 of the drawings, wherein the blade 42 is intermediatethe pair of break contacts associated therewith, if it is desired tomove blade 42 to the right into engagement with one break contactI 22,it will be necessary to.` insert operating handle 84 into bore "le ofthe mounting block to` thereby move the locking pin I5 inV the bore.inwardly against the bias of spring 8l)V and remove it from As soon asthe pin 16 in bore ll)v clears stop 82, the handle may be moved upwardlyor in a clockwise direction, as shown inV Fig. 1, to thereby moveactuating shaft 5E, crank 6|', and consequently,

. blade 42, in a similar direction until the blade engages the breakcontact on the right. Movement of blade 4.2 into engagement with eachbreak contact 22 is limited by adjustable stop bolts 63 positioned toengage opposite edges of the casting, in its extreme positionscorresponding to the extreme positionsV of blade42 in. engagement withAbreak contacts 22, respectively, to prevent damage to the contacts andoperating mechanism. When handle 84 is. removed` from bore 18 the switchwill be locked in this position because pin 7.6 will be positioned abovestop projection 82. v

Now, if it is desired to move the blade from engagement with the breakcontact 22 on the right into engagement with the break contact 22 on theleft, as viewed in Fig. 1, it is necessary thatjthe operating handle 84be insertedv in bore 10 to push back the pin 6` associated therewith'clear of projection 82 and thebl'ad'e may then be moved to theintermediate position shown in Fig. 1. Operating handle 84. will thenhave to be removed and inserted in bore 68 to move pin 16 in this boreinwardlx7 enough to clear stop 82 and permit movement' of the mountingblock downwardly below the position shown yin Fig. V1. Considering the'blade 42` to be in engagementY with the break contact 22. yat the.right, as viewed in Fig. 1, it is impossible to move the blade intoengagement with the other break contact without stopping at anintermediate position because it is essential that operating handle 84be in 'bore 70 to release blade 42.. Thereafter, movement of' the. bladefrom engagement withbreak contact 22 on the right towards the otherbreak Contact will be halted by engagement 'ot the pin l5 in bore 68 assoon as the. position shown inFig'. 1 is reached. YIt will thereupon benecessary to remove the handle from bore Til and insert it in bore 88 in-orderto move the blade into` engagement with break contact 22 scribedabove.

In view of the forego-ing, it is obvious that this invention preventsoperation. ofA a. switchA of the double-throw typefrom. engagement. withone set of contacts into engagement with another setof"` at the leftasde contacts without requiring that the switch be stopped at a positionintermediate the contacts to' change the mounting of the operatinghandle. This will clearly prevent rapid transfer of the switch bladefrom one set of contacts to another, and will also require apredetermined amount of time to complete a transfer operation, tothereby give the operator an opportunity to check the transfer operationwhile he is performing it. This delay required in the transfer operationwith the switch of this invention is, as previously7 pointed out,especially important when switching from one feeder line to another,because it gives syn* chronous apparatus an opportunity to come to astandstill before switching to another feeder which may be out ofsynchronism with the first feeder. Furthermore the same means isutilized to lockY the switch blade in engagement with each contact. Thestructure by which the desired objects are accomplished is particularlysimplied and eflicient, in that but few operating` parts are required toobtain the desired results.

Having described a preferred embodiment of the invention in accordancewith the patent statutes, it is desired that the invention be notlimited to this particular embodiment, because it will be obvious,particularly to those skilled in the art, that many modifications andchanges may be made inthis embodiment without departing from the broadspirit and scope of the invention. Therefore, it is desired that theinvention be interpreted as broadly as posible and that it be limitedonly as required by the prior art.

I claim as my invention:

1. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, means for locking said movable contact means at aposition intermediate said spaced contact means, said locking meansincluding parts for preventing movement of said movable contact means inopposite directions, respectively, actuating means adapted to beremovably associated with said movable contact means in two diierentpositions and cooperable with said parts of said locking means in saiddifferent positions, respectively, whereby when said actuating means isassociated with said movable contact means in one position, it isoperativ-e to release said locking means to permit actuation of saidmovable contact means only between said in-y termediate position and aposition wherein said movable contact means is in engagement with one ofsaid spaced contact means, and when said actuating means is associatedwith said movable contact means in the other of its diierent positionsit is operative to release said locking means to permit actuation ofsaid movable contact means only between said intermediate position andthe position wherein said movable contact means is in engagement withthe other of said spaced contact means.

2. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, latch means biased to latching position forreleasably latching said movable contact means at a positionintermediate said spaced contact means, said latch means includingseparate latch elements preventing movement of said movable contactmeans in opposite directions. respectively, actuating means adapted tobe removably associated with said movable contact means in `twodifferent positions and cooperable with said latch elements in saiddifferent positions, respectively, whereby when said actuating means isassociated with saidV movable contact means in one position, it isoperative to release said latch means to permit actuation of saidmovable contact means only between said intermediate position and aposition wherein said movable contact means is in engagement with one ofsaid spaced contact. means, and when said actuating means is associatedwith said movable contact means in the other of its different positionsit is operative to release said latch means to permit actuation of saidmovable contact means only between said intermediate position and theposition wherein said movable contact means is in engagement with theother of said spaced contact means.

3. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, means for locking said movable contact means at aposition intermediate said spaced contact means including a relativelynxed projection and a pair of spaced movable locking lugs associatedwith said mov,

able contact means for movement therewith and biased to positionswherein their paths of movement with said movable contact meansintersect and out of engagement with said spaced contact means,respectively, an actuating member for said movable contact means, arelatively stationary member adjacent said actuating member, aprojection on one of said members and spaced retractible lugs on theother of said members with said lugs normally positioned to lie onopposite sides of said projection in a position of said movable contactmeans intermediate said spaced Contact means to lock the parts in suchintermediate position, means biasing said lugs to their normalpositions, spaced mounting means o-n said actuating member for removablymounting an operating handle thereon at a plurality of differentpositions, said mounting means located relative to said lugs in a mannersuch that when said operating handle is mounted at one of said positionsit is effective to retract one of said lugs, and when mounted at anotherof said positions it is effective to retract the other of said lugs.

5. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, an actuating memberv tion of said movable contactmeans intermediate said spaced contact means to lock the parts in s suchintermediate position, means biasing said llugs to their normalpositions, spaced bores extending into said actuating member forremov-'L ably mounting an operating handle thereon at a plurality ofdifferent positions, said bores con-l structed and located relative tosaidA lugs inav manner such that when said operating handle is mountedat one of'said positions it is effective to,` retract one of said lugs,andV when mounted at another of said positions it is effective toretract the other ofk said lugs.

6. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with saidspaced contactmeans, respectively, a movably mounted actuating member for said movablecontact means, a relatively iixed projection, retractible lugs on saidactuating member with said lugs normally positioned to liel on oppositesides of said projection in a position of said movablecontact meansintermediate said spaced contact means to lock the parts in suchintermediate position, means biasing said lugs to their normallpositions, spaced mounting means on said actuating member ior removablymounting an operating handle thereon at a plurality of differentpositions, said mounting means located relative to said lugs in a mannersuch that when said operating handle is mounted at one of said positionsit is effective to retract one of said lugs, and when mounted at anotherof said positions it is eective to retract the other of said lugs.

'7. In av switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of Vengagement with said spaced contactmeans, respectively, a movably mountedactuating Vmember for said movablecontact means, a relatively iiXed' projection, retractible lugs on saidactuating member with said lugs normally positioned to lie on oppositesides of said projection in a position of said movable contact meansintermediate said spaced contact means to lock the parts in suchintermediate` position, means biasing said lugs to their normalpositions, spacedl bores extending into said actuating member forremovably mounting an operating handle thereon at a plurality ofdifferent positions, said bores constructed and located relative to saidlugs in a manner such that whensaid operating handle is mounted at oneof said positions in one oi said bores it is eectivle to retract one ofsaid lugs, and when mounted at another of said positions in another ofsaid bores it is effective to retract the other of said lugs.

8. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, a movably mounted actuating member for said movablecontact means, a relatively fixed projection, retractible lugs on saidactuating member with said lugs normally positioned to lie on oppositesides of said projection in a position of said movable contact meansintermediate said spaced contact means to lock the parts in suchintermediate position, means biasing said lugs to their normalpositions, spaced bores extending' into said actuating member forremovably mounting an operating handle thereon at a plurality ofdifterent positions, said boresrhaving lateral openings to receive partsassociated with said lugs,V respectively, whereby when said operatinghandle is mounted at one of said positions it is effective to retractone of said lugs, nd when mounted at another of said positions it iseffective to retract the other of said lugs.

9. In apparatus of the type described, a pluandere rality of switchescach of' which includes;y spaced; contacts and a movable contact meansadapted to be movedinto and out of engagement with sald spaced contacts,respectively, common` actuatingA` means` Vfor said: switches; includinga moya-bly mounted actuating member operatively associ. ated with said'movable contact means, mounting means movable with said actuating member'and having spaced'mountings for removably securingl an operating handleindifferent positions, 1oc k, ing means cooperable with said' mountingmeansto lock said movable contact means in a position intermediate saidspaced contacts, said' locking;- means including parts for preventingmovement of said movable contact means in oppositedireotions,respectively, said handle cooperable with said parts ofsaid lockingmeans in said differentA positions, respectively, whereby when said@handle is associated with said mounting means in one position it isoperative to release said locking means to permit actuationy of saidmovablecontact means only between said` intermediate position and aposition wherein said movable contact means is in engagement with one ofsaid spaced contact means, and when said handle is associated with saidmounting means in the other of its diierent positions it is operativetorelease said locking means to permit actuation of said movablecontactmeans only between said intermediate position and the positionwhereinsaid movable contact means is in engagement with the other ofsaid spaced contact means.

l0. In apparatus of the type described, a plurality of switches each ofwhich includes spaced contacts and a movable contact means pivotallymounted for movement into and out of engagement withsaid spacedIcontacts, respectively, a common operating shaft for said switchesopera-` tively associated with said movable contact means, mountingmeans onl said shaft and hav-` ingspaced mountings for removablysecuring an operating handle in different positions, locking meanslcooperable with said mounting means to lock said movable Contact meansin a position intermediate saidL spaced contacts, saidA locking meansincluding parts for preventing movementy of said movable Contact meansin opposite directions, respectively, said handle cooperable with saidparts of saidV lockingmea-ns in said diierent positions, respectively,whereby when said handle is associated with said mounting means in oneposition it is operative to release saidl lock-k ing means to permitactuation` of saidv movable contact means only between said intermediateposition and a position wherein said movable contact means is inengagement with one of said spaced( contact means, and Awhen said handleis'associated with said mounting means in the other ofjdiferentpositions itis operative to release said locking means to permitactuation of said movable contact means only between said intermediateposition and the position wherein said movable contact means is inengagement withv the other of said spaced contact,`

means.

1,1.InA a switch, a pair of spaced contact means, movable contact meansadapted to be moved in to and out of engagement with said, spacedjcontact means, respectively, an actuating member for said movablecontact means, an enclosure for said switch having an opening forrendering said actuating member accessible,` cooperating locking meanson said actuating member and enclosure for locking said movable contactmeans in a position in-.

termediate said spaced contact means, said locking means including partsfor preventingl movement of said movable contact means in oppositedirections, respectively, said actuating member having spaced handlemountings for receiving an actuating handle in different positions, saidhandle cooperable with said parts of said locking means in saiddifferent positions, respective- 1y, whereby when said handle isassociated with said actuating means in one position itis operative torelease said locking means to permit actuation of said-movable contactmeans only between said intermediate position and a position whereinsaid movable contact means is in engagement with one of said spacedcontact means, and when said handle is associated with said actuatingmeans in the other of its different positions it is operative to releasesaid locking means to permit actuation of said actuating means onlybetween said intermediate position and the position wherein saidactuating means is in engagement with the other of said spaced contactmeans.

12. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, an actuating member for said movable contact means,an enclosure for said switch having an opening for rendering saidactuating member accessible, said actuating member constructed tosubstantially close said opening and including a portion projectingthrough said opening, cooperating locking means on said actuating memberand enclosure for locking said movable contact means in a positionintermediate said spaced contact means, said locking means includingparts for preventing movement of said movable contact means in oppositedirections, respectively, said projecting portion of said actuatingmember having spaced handle mounting sockets for receiving an actuatinghandle in diierent positions, said handle cooperable with said parts ofsaid locking means in said different positions, respectively, wherebywhen said handle is associated with said actuating means in one positionit is operative to release said locking means to permit actuation ofsaid movable contact means only between said intermediate position and aposition wherein said movable co-ntact means is in engagement with oneof said spaced contact means, and when said handle is associated withsaid actuating means in the other of its different positions it isoperative to release said locking means to permit actuation of saidactuating means only between said intermediate position and the positionwherein said actuated means is in engagement with the other of saidspaced contact means.

13. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, a pivotally mounted actuating member for saidmovable contact means, an enclosure for said switch having an openingfor rendering said actuating member accessible, said actuating memberincluding a circular peripheral portion adapted to extend at least inpart through said enclosure opening, cooperating locking means on saidactuating member and enclosure for locking said movable contact means ina position intermediate said spaced contact means, said locking meansincluding parts for preventing movement of said movable contact means inopposite directions, respectively, said actuating member having spacedhandle sockets opening to the portion of said member exteriorly of saidenclosure for receiving an actuating handle in diierent positions, saidhandle cooperable with said partsof said locking means in said differentpositions, respectively, whereby when said handle is associated withsaid actuating means in one position it is operative to release saidlocking mea-ns to permit actuation of said movable contact means onlybetween said inter-1 mediate position and a position wherein saidmovable contact means is in engagement with one of said spaced contactmeans, and when said handle is associated with said actuating means inthe other of its different positions it is operative to release saidlocking means to permit actuation of said actuating means only betweensaid intermediate position and the position wherein said actuating meansis in engagement with the other of said spaced contact means.

14. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, a movably mounted actuating member for said movablecontact means, a relatively fixed projection, retractible lugs on saidactuating member with said lugs normally positioned to lie on oppositesides of said projection in a position of said movable contact meansintermediate said spaced contact means to lock the parts in suchintermediate position, spaced bores extending into said actuating memberfor removably mounting an operating handle thereon at a plurality ofdifferent positions, said bores having lateral openings for slidablyreceiving an end of said lugs, resilient means in said bores for biasingsaid lugs to their norrmal positions, whereby when said operating handleis mounted at one of said positions, it is effective to retract one ofsaid lugs, and when mounted at another of said positions, it iseffective to retract the other of said lugs.

15. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, means for locking said movable contact means at aposition intermediate said spaced contact means, actuating means adaptedto be removably associated with said movable contact means in twodifferent positions and cooperable with different portions of saidlocking means in said diierent positions, respectively, whereby whensaid actuating means is associated with said movable contact means inone position, it is operative to release said locking means to permitactuation of said movable contact means only between said intermediateposition and a position wherein said movable contact means is inengagement with one of said spaced contact means, and when saidactuating means is associated with said movable contact means in theother of its diilerent positions it is operative to release said lockingmeans to permit actuation of said movable contact means only betweensaid intermediate position and the position wherein said movable contactmeans is in engagement with the other of said spaced contact means.

16. In a switch, a pair of spaced contact means, movable contact meansadapted to be moved into and out of engagement with said spaced contactmeans, respectively, means for locking said movable contact means at aposition`4 intermediate said` spaced contactl means iand at spacedpositions wherein-v said movable contact means is in; engagement withsaid spaced projection, so that at said intermediate position saidprojection willl be positioned intermediate saidspaceddugs andat spacedpositions wherein said, movable contact meansengagessaid spaced contactmeansi bothflugs will 11e-positioned at opposite sides of said projectiomrespective1y,to prevent disengagement of saidI contact means,and actuating,` means adapted tol be removably associated with saidmovable contact meansin two diferent positions and cooperabieV with,said lugsin said positions, respectively. so as tol move Y therespective lug against its bias` to clearsaidprojection and permitmovement of said movable contact means into and out of. engagement withone of` said spaced contact means.

GORDON F. sAUERs,

